Hair conditioning agents are functional additives used in hair care products such as lotions, shampoos, creme rinses, mousses and setting gels to improve the tactile and physical properties of hair. Such properties include, for example, substantivity of the conditioning agent on the hair without excessive build-up and enhancement of hair manageability, i.e., wet combability, dry combability, neutralization of static charge generated by combing and ease of styling. Other properties include lubrication of the hair to reduce friction between hair and comb and to minimize tangling. The additive should also soften the hair and impart gloss to dull hair and smooth the feel of the hair by filling in gaps or flattening cuticle scales. It is also advantageous for the hair conditioner to improve set retention of the hair.
Cationic quaternary ammonium compounds, both mono- and di-functional, low molecular weight quaternary ammonium salts and certain high molecular weight polymers, are employed as conditioning additives in hair care products such as shampoos, conditioners, creme rinses, mousses, sprays and setting gels to impart wet and dry combability, improve feel, enhance curl retention and impart antistatic properties to hair. The Cosmetics, Toiletries and Fragrances Association (CTFA) has established a designation index for compounds employed in cosmetic and toiletry products. Two low molecular weight quaternary ammonium compounds that are commonly used in haircare products because of their low cost are stearylbenzyldimethylammonium chloride (CTFA designation--stearalkonium chloride) and cetyltrimethylammonium chloride (CTFA designation--cetrimonium chloride).
The high molecular weight, cationic quaternary ammonium polymers (polyquats) are being used increasingly in hair care products because of their reported advantages over the simple quaternary ammonium salts in enhancing wet combability, mending split ends and improving appearance. Commonly used polyquats include: UCARE.TM. Polymer JR (CTFA designation--Polyquaternium 10) from Union Carbide, a quaternized cellulose; Gafquat.TM. (CTFA designation--Polyquaternium 11) from International Specialty Products, a quaternized copolymer of vinylpyrrolidone and dimethylaminoethylmethacrylate; and Merquat.TM.550 (Polyquaternium 7) from Calgon, a homopolymer of dimethyldiallylammonium chloride.
These quaternary ammonium conditioning additives have in common the quaternary ammonium functional group: ##STR1## where R.sub.1 through R.sub.4 may be various substituted or unsubstituted alkyl or aryl substituents, or in the case of the polyquats, represent alkylene or arylene segments of a polymer chain. Associated with the positively charged quaternary ammonium nitrogen atom is a negatively charged counterion. This anion, X.sup.- may be a halide, hydroxide, methylsulfate or similar negatively charged group.
While it is known that copolymers of vinylpyrrolidone and quaternary ammonium compounds are used as hair conditioning additives in hair conditioning compositions, it is desirable to develop new polymers which can be used as a hair conditioning additive.